Up to now we've either been (a) resolving duplicates or (b) deferring them so
that we know to get back to the reporter [well, that's just me that's been doing
that, because resolving feels so weird, and shows up in the search logs].

What we really need is a 'duplicate' status that roundup will treat as resolved
(à la resolved-as-stable)

I guess one thing which was useful about not having duplicate is that it gives
us an intuitive view of how heavy a bug is (it shows up in the tracker a lot),
which is sometimes nicer than just a plain number but not scalable from a UI
standpoint.

I just added a 'duplicated' status.  Also changed a bunch of 'deferred' bugs to
'duplicated.'

David